to fossil fuel use mounts, nuclear costs rise (Portugal-Pereira et al. 2018) and renewables win out across the board. They already supply more than 26% of global electricity (REN21 2019), compared to nuclear power at around 10%, and are displacing fossil fuels in many markets.
Interestingly, under increasing pressure from renewables, some of the fossil and nuclear lobbies have therefore changed tack a little and are now arguing that renewables are still problematic since they cannot expand fast enough to deal with climate change (BP 2018a), with some climate change sceptics joining in (Lyman 2019), this after they have all resisted change and spent so long trying to stop renewables from getting started. Some of the incumbents may continue to resist, but over 185 companies so far have signed up to ‘100% by 2050’ renewable electricity targets (RE100 2019).
As argued above, what has changed things is not a sudden extra concern about climate or air pollution (although, as noted, that has happened and has helped) or even what some see as a collapse of nuclear power as a future option (WNISR 2019) but the fact that the cost of renewables has fallen dramatically. Arguably, a new economic dynamic has, at least partially, taken over, with renewables well placed to become the dominant option.
However, while the case for renewables does look strong, they are up against a set of well-established energy technologies, well entrenched in lucrative markets. The fossil fuel-based incumbents look to new carbon capture technology to allow them to stay in the game, and the nuclear lobby similarly looks to new technology to improve its economics. To set the scene, Box 1.2 provides a short summary of the main impacts of the options on offer, and I will be looking at the options, and at the issues raised by them, in more detail later.
Box 1.2 The new energy options – a summary of impacts and issues
The use of naturally and continuously replenished renewable energy flows, like the winds, waves, tides and solar heat/light, produces no direct carbon dioxide (CO2) or other emissions. There will be indirect emissions due to the use of fossil fuel for the construction of the technologies and for the production of associated materials, but that is true, at present, for all energy technologies. Once built, renewable energy-based power plants, like wind turbines and solar farms, differ from the rest in not needing any fuel to run. However, they may have some local impacts, and some (but not all) produce variable power outputs.
Those issues apart, they are strong ‘clean energy’ contenders, arguably more so than nuclear plants, which, although they do not produce CO2 in operation, rely on the use of fossil fuel to mine and process/enrich their fuel, a very energy-intensive process, thus incurring a carbon debt. There are also long-lived radioactive wastes to deal with, as well as the risk of leaks and unplanned release of radioactive material. Global fissile fuel reserves are also finite; they are not a renewed resource. Nuclear fusion, as opposed to fission, is still some way off as a practical option and may remain so but might have fewer fuel resource limitations, although there could still be risks and radiological implications.
It is possible to capture and store the CO2 produced by fossil fuel combustion plants, but, although that might allow us to continue to use fossil fuel, as I will be describing, there are operational and economic limitations to this arguably rather inelegant ‘end of pipe’ engineering approach to post-combustion ‘carbon capture and storage’. The environmental argument is that we should not be burning fossil fuel in the first place nor trying to find places to store the resultant CO2 safely and indefinitely. The global fossil fuel resource is in any case finite, so using it is not a long-term option, even ignoring CO2 and other emissions and impacts, for example in relation to air quality.
The combustion of biomass (plants, wood and other bio-materials), and then the capture and storage of the CO2 produced, is an option. In theory, since CO2 is absorbed when biomass is grown, that process would be carbon negative, reducing net atmospheric CO2 levels. However, to have a significant CO2 impact, in addition to vast CO2 storage requirements, very large amounts of biomass would have to be grown and burnt, with large land-use and ecological impacts.
The capture and storage of CO2 direct from the air is also possible, although that process would use energy rather than generate it. As an alternative, some of this CO2, or the CO2 from power plants, might be used to make new hydrocarbon fuels, if a source of hydrogen were available, for example produced using renewable energy. However, burning the resultant synthetic hydrocarbon fuels would release the CO2 again. It might be better to use the ‘green’ hydrogen direct as a fuel since its combustion only produces water vapour.
I will be coming back to these various options, issues and choices later, for example looking at costs, but from this short summary it does look as though, in terms of clean energy supply, renewables have the edge environmentally.
Can renewables deliver?
While in general terms the prospects for the future of renewables may look positive, and the overall case for alternatives may look poor, the resistance of incumbents, and some of the arguments against renewables that they have adopted, do have to be faced. A central issue raised is the question of whether renewables can expand rapidly enough to meet global energy needs.
This was met head on in a scenario published initially in 2009 in Scientific American (Jacobson and Delucchi 2009) and then more formally in 2011 (Jacobson and Delucchi 2011) and developed in their subsequent studies. It was suggested that a global target of obtaining 100% of all energy from renewables by 2050 was viable, at reasonable cost. That was ridiculed by critics as impossible, and there were debates over methodology (Clack et al. 2017). However, now, with several countries already above 50% and many dozens of further studies from around the world suggesting that very high renewables shares are possible (Stanford 2019), the debate is more about total-system costs and whether it will ‘only’ be 70%, or more than 80% (of electricity), globally by 2050 (IRENA 2017a), or how to do better than that (Bogdanov et al. 2019).
The pace of technical development and market adoption has been startling, taking even enthusiasts by surprise (for photovoltaic solar especially), and can be contrasted with the slow pace of development of the rival technologies, nuclear (Pearce 2017) and carbon capture and storage (Simon 2017).
As the head of the UK government’s advisory Committee on Climate Change put it, they had initially been ‘overly optimistic about cost falls in some other technologies – nuclear for example’, but for renewables ‘innovation has been the key – driven by policy – in ways that we did not fully expect ten years ago. Globally, a clear goal to decarbonise, with co-benefits of improved air quality in cities, has stimulated commercial innovation’ (Stark 2019a).
However, there are inevitably issues with renewables. Some of them have been highlighted in recent critiques from, amongst others, pro-nuclear lobbyist Michael Shellenberger. He says that renewables cannot power modern civilization, given that the energy sources are variable and also dilute and diffuse, requiring the use of large areas and involving significant local environmental impacts, as well as risks to human and animal life, along with high costs for backup requirements (Shellenberger 2019). He is not alone in challenging the viability of renewables. There is a range of critical books, articles and reports at varying levels of coherence (Lomborg 2019; Montford 2019; Rogers 2018).
It is relatively easy to provide specific counters to these challenges and to the assertion often made that ‘nuclear is a better bet than renewables’. For example, on cost, it is clear that many existing nuclear plants in the United States are having to close because they are no longer competitive (Abdulla 2018) and that, globally, few new nuclear projects are going ahead. By contrast, renewables are winning out economically in most countries (WNISR 2019).
On
